Okay, first off, I did not build it. It came with the house. Secondly, after the first time I heard scratching I did in fact set mouse traps! And they caught a single mouse. That was months ago, and the traps are still set. My cats go to town on the mice and shrews and weasels and stuff, though, so it doesn't seem to be an issue. Also, my dogs don't bark at it, so I don't think there is an animal trapped. There's also no noise when I go in there.

It's probably me hearing stuff! But it still doesn't make me feel very good. :c